George s



(No Model.)

G. S. LEE.

ROADWAY 0R PAVEMENT.

6 6 w m A 7 w m J Patented Dec. 18, 1888.

UNITED STATES PATENT OFFICE.

GEORGE S. LEE, OE DENVER, COLORADO, ASSIGNOR TO SAMUEL H. BAT IS, OF SAME PLACE.

ROADWAY OR PAVEM ENT.

SPECIFICATION forming part of Letters Patent No. 394,588, dated December 18, 1888.

Application filed November 22, 1887. Serial No. 255,912. (No model.)

To all whmn it ntay concern.-

Be it known that I, GEORGE S. LEE, a citizen of the United States, residing at Denver, in the county of Arapahoe and State of Colorado, have invented new and useful Improvements in Roadways or Pavements, of which the following is a specification.

My invention relates to the construction of roadways or pavements; and its object is to furnish a pavement or roadway of smooth surface, yet affording a good firm foothold for animals traveling thereon, economical in construction, yet durable; to which ends it consists in the features more particularly hereinafter described and claimed.

In the construction of my improved roadway I prefer to use the composition of matter described and claimed in my application of even date herewith and bearing Serial No.

255,911, which composition consists, essentially, of iron slag, the refuse or slag from gold and silver reduction-works, and a cementing material, such as asphalt.

Ordinarily in the construction of concrete or asphaltic pavements and roadways the coarser compositionthat is, the composition formed of the asphalt or cement and gravel or broken stone of some considerable size, say one or two inches diameteris placed at the bottom as the lower layer, while the upper layer, upon which comes all the grinding wear, is composed of cement or asphalt and sand or very finely-comminuted rock material, so that the composition most susceptible to the wear of travel is the one fully exposed thereto. This arises from the fact that the rock or gravel used is always harder than the cement or asphalt matrix in which it is embedded, and consequently wears away more slowly; hence if the coarsercomposition were used as the top or surface layer the cement or matrix under ordinary conditions would wear away faster than the embedded gravel or rock, either leaving the latter projecting above the general level of the road-bed, making the latter uneven, rough, and uncomfortable, or the gravel or rock would by the concussion of wheels, &c., be loosened from the matrix and removed therefrom, leaving the roadway pitted, the pits speedily enlarging into holes needing repairs. By the use of the composition noted, however, the coarser and betterwearing material or composition maybe used as the surface or wearing layer, inasmuch as the iron slag usedessentially in its composition an iron glass formed iirincipally of protoxide of iron and silicawears equally and evenly with the remainder of the materials used. hile very hard it is also brittle,

and while the asphalt or matrix is ground away by the action of vehicles passing thereover the slag is also ground away, leaving the surface level and even; at the same time, being used in this surface layer in a coarse form, it preserves a somewhat rough though level surface, affording a good firm foothold.

In laying my improved roadway or pave ment, the ground is first leveled. and the bed brought to the desired curve or radius. If

the bed-be on hard or clay soil, the laying may proceed thereon without further preparation than such leveling and proper tamping. If, however, the bed be on sandy or soft soil, it is preferable to fur the bed by spreading thereon a layer, a few inches in thickness, of

crushed slag, well tamped and compacted. The bed or foundation being thus prepared, the first layer or course is spread thereon, which is formed of the slag referred to, crushed so as to readily pass through a twenty-mesh screen,

and which forms about seventy-five per cent. of the bulk of the composition. To this is added about five per cent. each of talc and fire-clay and two per cent. of lime. These ingredients being thoroughly mixed, t re are added of such size as would pass through aninch 5 ring or even largerso as to place the heavier and better-wearing composition upon the surface. In order to unite the two layers the more thoroughly, and also to render the pavement more firm and to avoid danger of the com- This la er bein well com )acted a o I b i thereto on the top or bottom, or both, by

braces extending between them.

The construction of this pavement is illustrated in the accompanying drawing, which is a perspective view, partly in section, of my improved pavement.

In the View the reference-numeral 1 indicates the foundation or bed smoothed, compacted, and brought to the proper curve or radius between the sidewalks 8 8. this bed is laid the first layer 2, which is of the finer material, as before described. During the process of laying this layer longitudinally-arranged timbers 4 4 4 are partially embedded therein at proper intervals, as shown. WVhile these timbers may be of any desired size and at any suitable distances apart, Iprefer, as giving very good results, to use timbers either two by four or two by six inches in cross-section, and to place them four to six feet apart.

In order to stift'en and brace these main timbers themselves auxiliary cross-timbers may be used. These may be timbers 6, laid upon the tops of the timbers 4 and transversely thereto, and abutting against a central strip, 8, whereby an elastic support is given to the roadway.

3 3 represent the glittering, which, if of sep- Upon.

in each layer and totally inclosed by the two layers.

Having thus described my invention, what I claim is 1. A roadway or pavement consisting of two layers of composition composed, essentially, of iron slag from gold and silver reduction works, and a series of longitudinal and transverse timbers embedded in said composition, whereof the upper layer is the coarser, said transverse timbers having their ends abutting against a central longitudinal strip, substantially as described.

2. A roadway or pavement consisting of a series of longitudinal timbers, a series of transverse timbers having their ends abut ting against a central strip, and one or more layers of composition covering and inclosing the same, substantially as described.

In testimony whereof I affix my signature in presence of two witnesses.

GEORGE S. LEE.

Witnesses:

JAMES L. NoRRIs, J. A. RUTH RFORD. 

